We describe the generation of the simulation environment for the Sandbridge Sandblaster multithreaded processor. The processor model is described using the Sandblaster architecture Description Language (SaDL), which is implemented as python objects. Specific processor implementations of the simulation environment are generated by calling the python objects. Using just-in-time compiler technology, we dynamically compile an executing program and processor model to a target platform, providing fast interactive responses with accelerated simulation capability. Using this approach, we simulate up to 100 million instructions per second on a 1 GHz Pentium processor. This allows the system programmer to prototype many applications in real-time within the simulation environment, providing a dramatic increase in productivity and allowing flexible hardware-software trade-offs. This paper has been presented at the SAMOS IV workshop 2004.